Farmers and ranchers prefer to bale straw and hay before storage because baling compresses the material into a smaller, cohesive volume. A small and cohesive form makes handling and storage much easier.
Older balers formed bales that were perhaps 15 in. (40 cm.) by 15 in. (40 cm.) by 30 in. (80 cm.) and weighed typically from 35-75 lb. (16-35 kg.). Straw bales are less dense than hay bales, having density in the range of 6-10 lb./ft.3. Hay bales may have density in the range of 8-15 lb./ft.3. To some extent, the density is a function of the baler operation.
Newer types of balers form the loose straw or hay into larger bales having the shape of either large cylinders or rectangular prisms. One newer type of baler produces a rectangular bale that is 8 ft. (2.4 m.) long with a 3 ft. (0.9 m.) by 3 ft. (0.9 m.) cross section. Such a bale made from straw will weigh several hundred pounds (200-300 kg.), thus requiring power equipment for handling.
For purposes such as livestock bedding, straw must be loose to function efficiently. For this reason, farmers and ranchers convert baled straw back into a loose form before use, so that it absorbs animal waste efficiently. Loose straw also has landscaping applications such as for limiting erosion and for mulching roots.
These large bales prove difficult to convert into a loose form for spreading. When such bales were first available, farmers and ranchers moved them around with a tractor-mounted front end loader and then manually spread them with a fork. Farmers and ranchers found this to be difficult and time-consuming work.
Straw spreaders that mechanize this job are now available for smaller types of square bales and for larger round bales. However, the existing equipment designs for loosening and spreading larger rectangular straw bales are not widely accepted.
For large round bales, U.S. Pat. Nos. 4,142,686; and 4,448,361 each show a trailer for towing by a tractor, with the trailer carrying a unit for chopping and blowing the straw forming the bales. U.S. Pat. No. 4,790,489 shows a bale shredder that mounts on the rear of a tractor. Each of these patents shows a bale hopper or tub that rotates to continually present different parts of the bale's bottom surface to a chopping element.
Being carried by a trailer or rear-mounted on a tractor, these units are more difficult to maneuver in tight quarters such as a livestock barn. In particular, loading a square bale into a round hopper is difficult.
In view of these problems, currently available devices for processing large square straw bales for use as livestock bedding have deficiencies.